This forum uses cookies
This forum makes use of cookies to store your login information if you are registered, and your last visit if you are not. Cookies are small text documents stored on your computer; the cookies set by this forum can only be used on this website and pose no security risk. Cookies on this forum also track the specific topics you have read and when you last read them. Please confirm whether you accept or reject these cookies being set.

A cookie will be stored in your browser regardless of choice to prevent you being asked this question again. You will be able to change your cookie settings at any time using the link in the footer.

  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Active route in compass mode
#1
My tiny pilot is working well in both compass and gps mode.  If I am sailing in compass mode and activate a route in opencpn this affects the compass mode control setting and the boat veers off violently, also I noticed the mode had changed to gps mode.  Am I doing something wrong?
  Reply
#2
What happens if you switch between compass and gps mode without an active route?

Does activating the route in gps mode work ok?
.
  Reply
#3
This seems to be as per design, see this thread.
  Reply
#4
(01-01-2020, 03:06 PM)seandepagnier Wrote: What happens if you switch between compass and gps mode without an active route?

Does activating the route in gps mode work ok?
.

I have assumed that gps mode will not work without first activating a route as pypilot will not know which route to follow.  
My normal procedure is to use compass mode until the control is steady then activate a route and switch to gps mode. That is the procedure I have used with Raymarine and Simrad autopilots.
  Reply
#5
I can say I found a bug as you described in the first post sailing today. The problem was in the autopilot route plugin for opencpn, not pypilot.

pypilot works in both gps and compass mode. In gps mode if a route is not activated, it just follows the course, but using true north rather than the (possibly misaligned) compass course of magnetic heading.

If pypilot receives nmea APB while engaged, it will automatically switch to gps mode, and the heading to hold will be updated with each new APB message. The only exception is if it receives GPAPB message in which case it will ignore the message if the autopilot is in compass mode rather than switching automatically, so you can probably put this prefix 'GP' in opencpn to get this behavior.
  Reply
#6
(01-03-2020, 08:22 PM)seandepagnier Wrote: I can say I found a bug as you described in the first post sailing today.   The problem was in the autopilot route plugin for opencpn, not pypilot.

pypilot works in both gps and compass mode.   In gps mode if a route is not activated, it just follows the course, but using true north rather than the (possibly misaligned) compass course of magnetic heading.

If pypilot receives nmea APB while engaged, it will automatically switch to gps mode, and the heading to hold will be updated with each new APB message.    The only exception is if it receives GPAPB message in which case it will ignore the message if the autopilot is in compass mode rather than switching automatically, so you can probably put this prefix 'GP' in opencpn to get this behavior.

Thanks for looking into this.  If I activate a route while in compass mode I get a violent change in course, this may be because I have a 100 degree compass correction, have I done something wrong here?
I need to activate the route before changing to gps mode to ensure I will head to the correct waypoint. Can you please explain exactly what sentences I should be sending and receiving on my two data connections in opencpn?
Thanks for your help
John
  Reply
#7
(01-04-2020, 03:13 PM)oldjohn Wrote:
(01-03-2020, 08:22 PM)seandepagnier Wrote: I can say I found a bug as you described in the first post sailing today.   The problem was in the autopilot route plugin for opencpn, not pypilot.

pypilot works in both gps and compass mode.   In gps mode if a route is not activated, it just follows the course, but using true north rather than the (possibly misaligned) compass course of magnetic heading.

If pypilot receives nmea APB while engaged, it will automatically switch to gps mode, and the heading to hold will be updated with each new APB message.    The only exception is if it receives GPAPB message in which case it will ignore the message if the autopilot is in compass mode rather than switching automatically, so you can probably put this prefix 'GP' in opencpn to get this behavior.

Thanks for looking into this.  If I activate a route while in compass mode I get a violent change in course, this may be because I have a 100 degree compass correction, have I done something wrong here?
I need to activate the route before changing to gps mode to ensure I will head to the correct waypoint. Can you please explain exactly what sentences I should be sending and receiving on my two data connections in opencpn?
Thanks for your help
John

The violent change in course may be if it needs to make this course to follow the route.  It also could be if the boat isn't moving and the gps course or compass deviation is not well known. 

It really  depends, but if you activate a route that is behind you or to the side it will do this.    The easiest way to avoid this is to drag the starting waypoint on the route very near the boat just before activating.

It's also possible to get better control of the generation of apb messages using the autopilot route plugin.  The only nmea message pypilot receives for route following is $xxAPB.  


The course to hold should be displayed along side the actual heading in the pypilot opencpn plugin.   This course normally doesn't change but in route mode (apb messages received) it will constantly update this course.
  Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)